Idiopathic fibrosing mediastinitis

Chest X-ray features facilitate screening for pulmonary hypertension caused by fibrosing mediastinitis

Background

Misdiagnosis and underdiagnosis of pulmonary hypertension caused by fibrosing mediastinitis (PH-FM) are considerably prevalent due to unspecific symptoms and as well as the lack of awareness of this fatal disease.

Objectives

The aim of this study was to evaluate the diagnostic accuracy of the chest X-ray (CXR) for screening the patients with PH-FM from those with pulmonary hypertension (PH).

Design

This was a retrospective observational cohort study.

Methods

The patients with suspected PH were recruited between October 2014 and October 2020. All the clinical data and CXR findings were collected. The sensitivity, specificity, and likelihood ratio of the CXR features were calculated. Logistic regression was used to identify the factors associated with the CXR characteristics and FM and to generate a prediction model. Finally, the diagnostic efficiency of the prediction model was evaluated using nomogram and internal validation.

Results

The patients with PH-FM (n = 36) and PH caused by the diseases other than FM (PH-non-FM, n = 62) were enrolled. The CXR features, including atelectasis, pleural effusion, consolidation, nodules, calcification, interlobular septal thickening, and interstitial reticulation, were more prevalent in patients with PH-FM than in those with PH-non-FM (all p < 0.05). Atelectasis had a specificity of 97%, a sensitivity of 50%, and a greater accuracy for diagnosing of PH-FM [area under the curve (AUC) = 0.720; 95% CI: 0.634-0.806] than the other factors did. The combination of tuberculosis, natural logarithmic NT-proBNP (lnBNP), atelectasis, pleural effusion, and prominent right heart border constituted a prediction model to distinguish the PH-FM from the PH-non-FM, with a sensitivity of 91.7% and a specificity of 83.9%. The model demonstrated good prediction performance by showing an AUC of 0.922 (95% CI: 0.861-0.983) in the internal validation.

Conclusion

In this study, atelectasis was the most specific and accurate CXR characteristic for identifying PH-FM in the PH patients. The combination of atelectasis, pleural effusion, prominent right heart border, tuberculosis, and lnBNP constituted a prediction model that distinguished the PH-FM patients from the PH-non-FM ones with good performance.

Pulmonary Hypertension Caused by Fibrosing Mediastinitis

Pulmonary hypertension (PH) is a progressive and severe disorder in pulmonary hemodynamics. PH can be fatal if not well managed. Fibrosing mediastinitis (FM) is a rare and benign fibroproliferative disease in the mediastinum, which may lead to pulmonary vessel compression and PH. PH caused by FM (PH-FM) is a pathologic condition belonging to group 5 in the World Health Organization PH classification. PH-FM has a poor prognosis because of a lack of effective therapeutic modalities and inappropriate diagnosis. With the development of percutaneous pulmonary vascular interventional therapy, the prognosis of PH-FM has been greatly improved in recent years. This article provides a comprehensive review on the epidemiology, pathophysiologic characteristics, clinical manifestations, diagnostic approaches, and treatment modalities of PH-FM based on data from published reports and our medical center with the goal of facilitating the diagnosis and treatment of this fatal disease.

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PH-FM, as a type of rare condition in group 5 PH, has a poor prognosis because of a lack of effective therapeutic modalities and frequent misdiagnosis and underdiagnosis.

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The most prevalent trigger of FM is H-FM in the United States and TB-FM in China.

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Imaging findings, including mismatched perfusion defects in the V/Q scan, FM dyad, and FM triad are important diagnostic clues, and clinical classification facilitates decision making in diagnosis and therapeutics.

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Because of the limited efficacy of drug therapy as well as the uncertain effectiveness and high risk of surgical treatment, endovascular interventional modality is currently the preferred therapeutic option, although procedure-related complications and intrastent restenosis after PV intervention need to be addressed.